This invention relates to a system for treating wastewater and more particularly for the treatment of wastewater including the use of filtering materials as aerobic biofilters in a biofilter treatment tank.
In the treatment of wastewater, such as sewage and the like, it is common to provide a septic tank with an inlet in an upper portion to receive the wastewater. The septic tank is provided with, and generally on the opposite side from the inlet, an outlet discharge which is in flow communication with laterals for discharging effluent into an open field or the like. In the septic tank, the particulate materials settle to the bottom and it is the effluent which is removed through the laterals. Moreover, it has become common practice to install filters at the outlet discharge from the septic tank to remove undissolved solid particulate materials thereby preventing said materials from entering into the lateral field.
In recent years, it has been suggested to even further treat effluent from a septic tank before the wastewater is left to the environment. For example, U.S. Pat. No. 5,980,739 to Jowett et al teaches a wastewater treatment system including an aerobic filter medium, particularly polyurethane foam particles and the like, as a biofilter. Also, U.S. Pat. No. 5,762,784 also to Jowett et al teaches a water treatment apparatus which includes a container having apertures through the walls thereof and being opened to the atmosphere filled with open celled foam material for use in the treatment of wastewater.
It is an object of the present invention to provide a wastewater treatment system to treat organic matter, solids, and pathogens.
It is also an object of the present invention to provide a wastewater treatment system for treatment of organic matter, solids, and pathogens which is relatively inexpensive and easy to install and maintain.
More particularly, the present invention is directed to a method for treating wastewater wherein water received within a septic tank is either pumped or gravity fed to a container having a body of filter material therein wherein the wastewater is generally sprayed along the top of the body of filter material and is allowed to percolate slowly downwardly therethrough. The filtered wastewater is collected in the bottom of the container and then transferred by pump or gravity into laterals, or the like, or to other parts of the environment, or is recycled for further treatment.
Even more particularly, the present invention is directed to a wastewater treatment system which includes a septic tank in flow communication with at least one container having a body of filter material therein. An inlet to the container is in flow communication with an outlet from the septic tank. The inlet to the container includes spray nozzles to spray effluent over the body of filter material into the at least one container, the inlet including a conduit extending along the upper portion of the container. The filter material is preferably open-cell foam material in randomly stacked cubes within the container which provides for a filter medium having large openings or spaces therein so that the growth of biomatter does not plug nor unduly interfere with the filtration of the wastewater as it descends or percolates downwardly therethrough. Moreover, the container is a solid wall container with a lid loosely placed thereon or includes an opening in the lid so that there is an adequate supply of oxygen into the container to assist in the degradation of the organic matter and pathogens therein. The system may also include a recycle tank having an inlet in flow communication with the outlet from at least one container wherein the recycle tank includes two outlet conduits, one in flow communication with the septic tank and the other in flow communication with the environment or is transferred for further treatment.